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# EightBall Compiler and Virtual Machine
## What is it?
The EightBall Virtual Machine is a simple runtime VM for executing the bytecode produced by the EightBall compiler. The EightBall VM can run on 6502 systems (Apple II, Commodore VIC20, C64) or as a Linux process.
## How to use it?
The EightBall system is split into two separate executables:
- EightBall editor, interpreter and compiler
- EightBall VM, which runs the code built by the compiler
On Linux, the editor/interpreter/compiler is `eightball` and the Virtual Machine is `eightballvm`.
On Apple II ProDOS, the editor/interpreter/compiler is `eightball.system` and the VM is `8bvm.system`.
On Commodore VIC20, the editor/interpreter/compiler is `8ball20.prg` and the VM is `8ballvm20.prg`.
On Commodore C64, the editor/interpreter/compiler is `8ball64.prg` and the VM is `8ballvm64.prg`.
Here is how to use the compiler:
- Start the main EightBall editor/interpreter/compiler program.
- Write your program in the editor.
- Debug using the interpreter (`run` command).
- When it seems to work work okay, you can compile with the `comp` command.
The compiler will dump an assembly-style listing to the console and also write the VM bytecode to a binary file called `bytecode`. If all goes well, no inscrutable error messages will be displayed.
Then you can run the VM program for your platform. It will load the bytecode from the file `bytecode` and execute it. Running compiled code under the Virtual Machine is much faster than the interpreter (and also more memory efficient.)
## VM Internals
See `eightballvm.h` for technical details.